Log Unicode exception instead of printing them to the console when they occur building the email alias files.

- Legacy-Id: 18909

ietf/utils/aliases.py

@@ -17,6 +17,7 @@ Mailing list alias dumping utilities
 
 
 from django.conf import settings
+from ietf.utils.log import log
 
 import debug                            # pyflakes:ignore
 
@@ -75,7 +76,7 @@ def dump_sublist(afile, vfile, alias, adomains, vdomain, emails):
         # If there's unicode in email address, something is badly
         # wrong and we just silently punt
         # XXX - is there better approach?
-        print('# Error encoding', alias, repr(emails))
+        log('Error encoding email address for an %s alias: %s' % (alias, repr(emails)))
         return []
     return emails